package com.lagou.edu.intercepter;

import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Created by Ju·Felix on 2020/5/5.
 */
public class LoginIntercepter implements HandlerInterceptor {

    /**
     * 登录验证只需要实现preHandle方法
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        //获取请求的RUi:去除http:localhost:8080这部分剩下的
        String uri = request.getRequestURI();

        //UTL:除了login.jsp是可以公开访问的，其他的URL都进行拦截控制
        if (uri.contains("login")) {
            return true;
        }

        //获取session
        HttpSession session = request.getSession();
        String username = (String) session.getAttribute("username");

        //判断session中是否有用户数据，如果有，则返回true，继续向下执行
        if (username != null) {
            return true;
        }

        //不符合条件的给出提示信息，并转发到登录页面
        request.setAttribute("msg", "您还没有登录，请先登录！");
        request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response);
        return false;
    }

}
